In an existing LTE (Long-Term Evolution, long Term evolution) system, when selecting an initial cell, a UE (User Equipment, user equipment) searches for a radio frequency channel in an E-UTRA (Evolved UMTS Terrestrial Radio Access, evolved UTMS terrestrial radio access) frequency band according to its own capabilities so as to find a proper cell. For each carrier frequency, the UE only searches for a cell with strongest signals and selects the cell as a serving cell.
The present cell selection is determined according to RSRP (Reference Signal Received Power, reference signal received power) signal strength or SCH_RP (Synchronization Channel Received Power, synchronization channel received power) signal strength of the cell and a cell selection parameter which is in broadcast information. For a specific carrier frequency, the UE makes a cell selection decision on only one cell that has strongest RSRP signal strength or SCH_RP signal strength. The so-called cell selection decision is a decision based on an S rule and according to the cell selection parameter in the broadcast information.
An LTE-A (Long-Term Evolution Advanced, long term evolution advanced) system is a heterogeneous network, and it is a mixed scene where low-power cells such as a pico cell (pico cell, hotzone), a femto cell (femto cell, HeNB), and a relay node (relay node, RN) cell are included in the coverage of a macro cell (macro cell, eNB). Therefore, in a heterogeneous network scene, uplink signals sent by the UE cause serious interference in the network.